Topic : The ATARI Compendium
Author : Scott Sanders / JAY Software
Version : 1.25 (20/6/2003)
Subject : Documentation
Nodes : 1117
Index Size : 32614
HCP-Version : 6
Compiled on : Atari
@charset : UTF-8
@lang : en
@default :
@help : %About
@options : +g -i -t4 +y +z
@width : 100
View Ref-FileProgrammable Sound Generator (YM 2149)Location(s) SizeBYTE Occupies one byte (8 bits).
WORD Occupies one WORD (16 bits).
LONG Occupies one longword (32 bits).
OW Occupies the odd WORD of a LONG.
EW Occupies the even WORD of a LONG.
OB Occupies the odd BYTE of a WORD.
EB Occupies the even BYTE of the WORD.
MchnIf the box is shaded then address is available
for this computer.
▒ ▒ ▒ ▒ ▒ ▒
| | | | | '------- Falcon030
| | | | '--------- TT030
| | | '----------- MEGA STe
| | '------------- STe
| '--------------- MEGA ST
'----------------- STTypeROM Location is Read-Only Memory
RAM Location is Read-Write Memory
I/O Location is hardware-mapped
VME Location addresses VME address space
N/A Not applicable
RO Read-only location
WO Write-only location
RW Read-write location
RSVD Reserved
Unassigned Either not assigned or undocumented
Meaning (see Usage)
▒▒▒▒▒▒
0x00FF8800 EB ▒▒▒▒▒▒ I/O PSG Read (Read only on I/O port B) / PSG ▒▒▒▒▒▒ Register Select (WO) Reading this location
▒▒▒▒▒▒ yields data from the parallel interface
▒▒▒▒▒▒ Writing to bits 0-3 of this location
▒▒▒▒▒▒ selects a PSG register to address as
▒▒▒▒▒▒ follows:
▒▒▒▒▒▒
▒▒▒▒▒▒ Value Register
▒▒▒▒▒▒ 0000 Channel A Fine Tune
▒▒▒▒▒▒ 0001 Channel A Coarse Tune
▒▒▒▒▒▒ 0010 Channel B Fine Tune
▒▒▒▒▒▒ 0011 Channel B Coarse Tune
▒▒▒▒▒▒ 0100 Channel C Fine Tune
▒▒▒▒▒▒ 0101 Channel C Coarse Tune
▒▒▒▒▒▒ 0110 Noise Generator Control
▒▒▒▒▒▒ 0111 Mixer Control _ I/O Enable
▒▒▒▒▒▒ 1000 Channel A Amplitude
▒▒▒▒▒▒ 1001 Channel B Amplitude
▒▒▒▒▒▒ 1010 Channel C Amplitude
▒▒▒▒▒▒ 1011 Envelope Period Fine Tune
▒▒▒▒▒▒ 1100 Envelope Period Coarse Tune
▒▒▒▒▒▒ 1110 I/O Port A Select (Write only)
▒▒▒▒▒▒ 1111 I/O Port B Select
▒▒▒▒▒▒
▒▒▒▒▒▒
0x00FF8802 EB ▒▒▒▒▒▒ I/O When I/O Port A is selected, this location
▒▒▒▒▒▒ contains the PSG Write Data (WO) register
▒▒▒▒▒▒ as follows:
▒▒▒▒▒▒
▒▒▒▒▒▒
▒▒▒▒▒▒
▒▒▒▒▒▒
▒▒▒▒▒▒
▒▒▒▒▒▒
▒▒▒▒▒▒
▒▒▒▒▒▒
▒▒▒▒▒▒
▒▒▒▒▒▒
▒▒▒▒▒▒
▒▒▒▒▒▒
▒▒▒▒▒▒
▒▒▒▒▒▒
▒▒▒▒▒▒
▒▒▒▒▒▒ When I/O Port B is selected, this
▒▒▒▒▒▒ locations accesses the Parallel Port Data
▒▒▒▒▒▒ Register (WO)
▒▒▒▒▒▒
▒▒▒▒▒▒
0x00FF8804 - N/A ▒▒▒▒▒▒ I/O Unassigned
0x00FF88FF ▒▒▒▒▒▒
▒▒▒▒▒▒